1. Field of the Invention
The present invention relates to medical devices and methods for testing neurocognitive capability by measurements of humans using an EEG (electroencephalograph) and physiological function monitoring system.
2. Description of the Related Art
At the present time there is considerable interest in testing the performance ability of those engaged in certain types of work. For example, recently in New York City a subway train derailed because the motorman was drunk, killing passengers and shutting down a vital subway line for a week.
The issue of safety is of prime importance in many activities, such as public transportation and nuclear plant operation. There is a widespread concern of increased instances of substance abuse, including the use of cocaine, alcohol, etc., by those entrusted with the safe operation of public vehicles such as airplanes, railroads and buses, as well as those who operate facilities which require a high degree of attention, such as nuclear power plants, chemical plants and military facilities.
A program of random drug and alcohol testing has been suggested and in some cases implemented. However, those tests, since they test only a few employees each week, may overlook those employees whose performance sometimes fails, but whose performance does not fail regularly. That type of program may be resisted as being intrusive into the employee's life, since it may involve a blood and urine test.
A performance type of testing program has recently been tried in a few transportation systems in which each employee, before he/she starts work, takes a simple eye-hand coordination test using a digital computer having a screen. For example, a spot is randomly shown on the screen and the person being tested has to move the cursor, using a mouse input device, to cover the spot. This type of performance testing has generally been accepted by employees and their unions because it is non-invasive and seems to be objective.
Performance testing has important advantages over chemical testing:
(i) It detects worker impairment before the employee goes on the job. Chemical testing does not;
(ii) Performance testing discovers impairment for any reason (for example, a hangover or anxiety about a sick child). Chemical testing does not; and
(iii) Performance testing is cheaper than chemical testing and less invasive. While workers commonly resent chemical testing (often having to urinate in a cup in front of witnesses), the majority do not mind performance testing.
Performance testing is gaining acceptance as the preferable method for workers in sensitive positions like train drivers. However, performance testing has the basic fault that it passes some employees who should not be allowed to go to work. For example, a partially drunk employee, or one partially high on drugs, or one over-fatigued, may pass the test by concentrating on the test. When a person places his/her concentration on passing a short eye-hand coordination test, in many cases the test will be passed, although the person would otherwise fail and should not be allowed to work in a position where safety is important.